The present invention relates generally to a current sense read amplifier, a memory circuit comprising the current sense read amplifier, and more particularly to a processor comprising the memory circuit and a method for amplifying a data signal on a bitline.
Integrated circuits are used for a diverse number of electronic applications, from simple devices such as wristwatches to the most complex computer systems. Low power circuits are becoming more prevalent due to a desire for lower power consumption. In particular, power dissipation has become a limiting factor for the yield of high performance circuit designs (operating at frequencies of one gigahertz and above) fabricated in deep sub micrometer technologies. Low power designs are also preferable, since they exhibit less power supply noise and provide better tolerance with regard to manufacturing variations. Furthermore, users ask for larger and faster memory, which increases the power consumption.
In a semiconductor memory device such as a dynamic random access memory (DRAM) or a static random access memory (SRAM), data read in a read operation sequentially passes through a plurality of sense amplifiers and is then output. Since a memory cell has a low signal drive capability, the data signal is amplified by a one or more bitline read amplifiers until it eventually reaches the memory output.
Recent trends have seen an increase in integration density of semiconductor memory devices and a reduction of a voltage thereof. An increase in the density results in an increase in the load capacitance across data lines reducing the read speed of the memory device.
To address this problem, US 2011/0069568 A1 proposes a semiconductor memory device that includes a plurality of memory cell array blocks, a bitline sense amplifier, a local sense amplifier that can be controlled to be turned on or off, a data sense amplifier, and a controller.
As technology advances and approaches the 14 nanometer semiconductor device fabrication node, further improvement in power consumption may be desirable.